Hi adict_drek,
I think this is suffering from you trying to get far too much into one image. If you want to have the grim reaper in there then you need to make him the focus of the image at the sacrafice of the environment. We will never be able to see the grim reaper properly unless he is very clear in frame (maybe either 2/3rds grim reaper 1/3 environment or vice versa in your frame).

You mentioned studying lighting and composition, but this is definitely still lacking in those two areas. Things are almost totally symetrical at the moment which is rarely a good idea, and the dark wave at the back kills any depth that you could get into the image. There also are no discernable shadows in the painting, and light is almost more about creating good shadows than it is about the highlights. They work in tandem though - strong light will mean a strong shadow (unlessthereis a strong fill source or bounce light but that can probably come in later).
Lighting also plays a large part on your colour palette. I think you may be approaching your colour palette in the wrong way as it currently just looks like variations in value and saturation of just one hue. A good colour palette will have all the range and cohesion that a natural environment does. Have a look through your photos, I bet you have never taken a photograph that only contains lighter or darker red, even in the reddest of sunsets.

It sounds like your thinking is definitely on the right track, but it seems to not be quite coming together in your image. Can you post the studies you have been doing? It might be worth starting a thread for those so that some of the guys here can help guide those and make sure you are able to apply the principles to your own work.

Hope it helps, i didnt want this post to sound discouraging or anything, just to help get this to where it can be if you continue your dedication!